Second round leaderboard

Scott got off to a slow start on Friday with five straight pars and although he two-putted the par-five sixth for his first birdie of the day, he promptly gave that shot back on the next after failing to get up and down from a greenside bunker.

Another bogey looked possible on the ninth after his drive into the rough left him with an awkward angle to the green, but a superb approach to 10 feet actually set up another birdie.

Scott's birdie attempt on the 10th caught the edge of the hole and span out, but that proved to only be a temporary blip as he holed from four feet on the 11th and five feet on the 12th.

Further birdies on the 16th and 17th took Scott eight clear of the field and a superb drive down the last left him just 150 yards from the pin, but he paid the price for a conservative approach, three putts from 50ft for a bogey dropping him back to 14 under par.

"I think it was a pretty good way to back up a low round," Scott said. "It's not easy to do that, especially around a tough course.

"The first hole was key in keeping some momentum out of yesterday, making kind of a scrappy par and a good putt on the first to feel like I'm heading in the right direction to start the day.

"Then I played really solid. I would say I struck the ball much better, but just didn't quite make the putts. But it's tough to do that all the time around a track like this.

"If it stays like this it will be firmer again. This course will really start to bare its teeth.

"I've got to take in the attitude of starting over again and trying to play a really hard 36 holes. And hopefully if I can keep striking the ball like I am I'll give myself enough chances for birdie and hopefully more birdies than bogeys."

Rose crashes out, GMac survives

Italy's Francesco Molinari and American duo JB Holmes and Chesson Hadley were Scott's closest challengers on seven under par, with Welshman Jamie Donaldson carding a 71 to lie six under alongside former US PGA champion Keegan Bradley and Brandt Snedeker.

Ian Poulter also returned a 71 to lie five under, but it was not such a good day for his Ryder Cup team-mate and fellow Orlando resident Graeme McDowell, who followed his opening 68 with a second round of 77 that did not feature a single birdie.

After starting from the 10th, McDowell dropped shots at the 13th and 18th to be out in 38 and then finished in nightmare fashion with a double-bogey on the eighth and bogey on the ninth.

McDowell at least made the cut on one over par, while US Open champion Justin Rose made an early exit after crashing to a second round of 79.

Rose carded six bogeys, two double bogeys and three birdies to finish three over par, 17 shots behind playing partner Scott.